Data of download installation package is lost or damaged. The signature exception cannot be forced to install. The signature is abnormal due to inconsistent signature caused by repeated installation of the software, so it is necessary to uninstall and reinstall the software. Inconsistent signatures may be caused by the loss or damage of downloaded installation package data, unstable connection between the currently used network and the upgrade server, packet loss when downloading the system update package, or failure in checking the update package. You can download and install again when the network conditions are good.